What is the speed of jet in still air and the speed of the wind

Question

A jet fly against the wind with 5520 mi in 6 hours .With the the wind the same jet fly 9100 mi in 7 hours

Answer 1

One jet: (s - w)6 = 5520

Other jet: (s + w)7 = 9100

 

6s - 6w = 5520

7s + 7w = 9100

 

42s - 42w = 38640

42s + 42w = 54600

 

84s = 93240

s = 1110